To prolong tumor retention time and improve pharmacokinetics, based on the multivalent effect of PSMA, a series of PSMA small molecules with different valence states were successfully designed and synthesized, followed by structural optimization by PEG4, namely DOTA-(1P-PEG4), DOTA-(2P-PEG0), DOTA-(2P-PEG4), and DOTA-(2P-PEG4)2 (Scheme 1). This evidence concerns the gene FOLH1 and neoplasm.